Tonneau covers have been successfully commercialized by the Shur Company of Yankton, S. Dak. and are described in various patent documents, including Spencer, U.S. Pat. No. 6,568,740; Dimmer, U.S. Pat. No. 6,575,520; and Spencer, US Patent Publication No. 2004/0212212.
Tonneau covers are used in conjunction with the cargo box of pickups to protect items placed in the cargo box from exposure to dirt, debris, and other environmental contaminants. Tonneau covers are also used to enhance the aesthetic appearance of the pickup.
There are two main types of tonneau covers—hard and soft. The hard tonneau covers include one or more pieces that when placed in a closed position form a generally rigid cover over the cargo box. In contrast, the soft tonneau covers are fabricated from a soft material. When the soft tonneau covers are not being used, they may be rolled up to expose the interior of the cargo box.
To decrease the time associated with installing the tonneau covers and enable the tonneau cover to be readily removed, various tonneau cover attachment mechanisms have been developed. One configuration for clamps used in conjunction with tonneau covers has two clamp members that interlock at a pivot point and are forced together by tightening a threaded fastener. When the fastener is tightened using a wrench or other tool, the clamp members are urged together to force a portion of the tonneau cover into frictional engagement with a side of the pickup cargo box.
One such clamping system is described in Dimmer, U.S. Pat. No. 6,568,740, which is assigned to the assignee of the present application. The Dimmer clamp includes two clamping sections that are pivotally mounted together and held together with a bolt.
Another clamping system is discussed in Wheatley, U.S. Pat. No. 6,893,073. Similar to the Dimmer clamp, the Wheatley clamp includes two clamping sections that are operably attached to each other with a bolt. Still another clamping system is discussed in Kerstling, U.S. Pat. No. 5,540,475. The Kerstling clamp has a two-part configuration and is operable by manually moving a clamp handle.